The present invention relates to a catalyst system for producing ethylene copolymers in a high temperature solution process, the catalyst system comprising (i) a metallocene complex of a group 4 transition metal comprising at least one ligand selected from optionally substituted cyclopentadienyl (Cp), indenyl (Ind) and fluorenyl (Flu) ligands and (ii) a solid alkyl aluminium oxide cocatalyst The invention relates also to the preparation of the catalyst system, use thereof in the high temperature solution process and to a process comprising polymerizing ethylene and a C.sub.4-10 alpha-olefin comonomer in a high temperature solution process in the presence of the catalyst system.

The present invention relates to a supported catalyst comprising a novel metallocene compound having excellent polymerization activity, and a method for producing polypropylene comprising polymerizing propylene in the presence of the catalyst. The supported metallocene-catalyst of the present invention can produce a polypropylene having a relatively narrow molecular weight distribution and a SPAN value.

Processes are provided which include copolymerization using two different metallocene catalysts, one capable of producing high Mooney-viscosity polymers and one suitable for producing lower Mooney-viscosity polymers having at least a portion of vinyl terminations. The two catalysts may be used together in polymerization to produce copolymer compositions of particularly well-tuned properties. For instance, polymerizations are contemplated to produce high-Mooney metallocene polymers that exhibit excellent processability and elasticity, notwithstanding their high Mooney viscosity. Other polymerizations are also contemplated in which lower-Mooney metallocene polymers are produced, which also exhibit excellent processability and elasticity, while furthermore having excellent cure properties suitable in curable elastomer compound applications. Many of the contemplated polymerizations include controlling the ratio of the two metallocene catalysts used in the polymerization so as to obtain the desired Mooney viscosity and desired rheology (indicated by Mooney Relaxation Area) of the copolymer compositions.

The present disclosure provides a hybrid supported metallocene catalyst useful for preparing a polyethylene copolymer capable of producing an mLLDPE shrink film having excellent shrinkage and processability with excellent mechanical properties, and a process for preparing a polyethylene copolymer using the same. The hybrid supported metallocene catalyst comprises at least one first metallocene compound selected from compounds represented by the following Chemical Formula 1 and at least one second metallocene compound selected from compounds represented by the following Chemical Formula 2:

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The present disclosure relates to a polyethylene having high pressure resistance and a crosslinked polyethylene pipe including the same. The polyethylene according to the present disclosure has high melt index and density and exhibits a sufficient degree of crosslinking, thereby exhibiting excellent strength and pressure resistance characteristics.

Provided are a novel metallocene-supported catalyst and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure may be used in the preparation of polyolefins, it may have excellent activity and excellent reactivity with comonomers, and it may prepare olefinic polymers having a high molecular weight and a low molecular weight.

A novel transition metal compound and a catalyst composition including same are disclosed herein. In some embodiments, the transition metal compound is represented by formula 1 disclosed herein. In some embodiments, the catalyst composition comprises the transition metal compound represented by formula 1. The catalyst composition may be useful for preparing an olefin-based polymer having a high molecular weight in a low density region, and may be useful for preparing an olefin-based polymer having a low melting index (MI) in high temperature conditions and a high molecular weight.

The present invention relates to a process for preparing a catalyst for olefin polymerization. Specifically, the present invention relates to a process for preparing a supported metallocene catalyst capable of producing a polyolefin in which the formation of gels is suppressed. In the process for preparing a supported metallocene catalyst according to an embodiment of the present invention, it is treated with a metallic stearate after a transition metal compound has been supported, which suppresses the formation of a macromolecular polyolefin. Thus, a polyolefin with minimal gel formation can be prepared.

Provided is an ethylene/1-hexene copolymer which has excellent long-term physical properties and processability, and thus may be usefully applied to manufacturing high-pressure resistant heating pipes, PE-RT pipes, large-diameter pipes, or the like.

The present invention relates to a polyethylene copolymer which has excellent processability and long-term durability, and thus is useful for hollow molding of a pipe or the like.